Hmm.. Sounds like you're coming from the right place!
The majority of maps that'll be done on these engines will be a generic map purchased, then they might drive the car and log it and compensate slightly for any variables that don't fit perfectly within the 'off the shelf map.' This is like buying a suit in M&S and taking it to a tailor and having the sleeves rolled up 1/4" inch.
The alternative is 'Live Mapping' which is performed on a dynograph by a very skilled operator who'll directly code the hex to extract exactly what you're after.... This, as I'm sure you'll appreciate is highly skilled and expensive.... Rarely (if ever) I guess done on NA petrol engines, don't pay for this on this vehicle. This is having a suit made by a tailor.
If I was in your position (and remember I only 'dabble' in the most basic sense in remapping/coding) I'd go ahead but make sure all your modifications are in place, car serviced and about as good as it'll get before you go for the mapping.
I'd say, and I've not tried it in your situation, that you'll get gains certainly, night and day difference? That depends on your own perception but I'd wager you won't notice a vast difference.
If you're playing the numbers game though, it needs to be done.